xref: /linux/drivers/misc/lan966x_pci.c (revision fcc79e1714e8c2b8e216dc3149812edd37884eef)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Microchip LAN966x PCI driver
4  *
5  * Copyright (c) 2024 Microchip Technology Inc. and its subsidiaries.
6  *
7  * Authors:
8  *	Clément Léger <clement.leger@bootlin.com>
9  *	Hervé Codina <herve.codina@bootlin.com>
10  */
11 
12 #include <linux/device.h>
13 #include <linux/irq.h>
14 #include <linux/irqdomain.h>
15 #include <linux/module.h>
16 #include <linux/of_platform.h>
17 #include <linux/pci.h>
18 #include <linux/pci_ids.h>
19 #include <linux/slab.h>
20 
21 /* Embedded dtbo symbols created by cmd_wrap_S_dtb in scripts/Makefile.lib */
22 extern char __dtbo_lan966x_pci_begin[];
23 extern char __dtbo_lan966x_pci_end[];
24 
25 struct pci_dev_intr_ctrl {
26 	struct pci_dev *pci_dev;
27 	struct irq_domain *irq_domain;
28 	int irq;
29 };
30 
31 static int pci_dev_irq_domain_map(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw)
32 {
33 	irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq);
34 	return 0;
35 }
36 
37 static const struct irq_domain_ops pci_dev_irq_domain_ops = {
38 	.map = pci_dev_irq_domain_map,
39 	.xlate = irq_domain_xlate_onecell,
40 };
41 
42 static irqreturn_t pci_dev_irq_handler(int irq, void *data)
43 {
44 	struct pci_dev_intr_ctrl *intr_ctrl = data;
45 	int ret;
46 
47 	ret = generic_handle_domain_irq(intr_ctrl->irq_domain, 0);
48 	return ret ? IRQ_NONE : IRQ_HANDLED;
49 }
50 
51 static struct pci_dev_intr_ctrl *pci_dev_create_intr_ctrl(struct pci_dev *pdev)
52 {
53 	struct pci_dev_intr_ctrl *intr_ctrl __free(kfree) = NULL;
54 	struct fwnode_handle *fwnode;
55 	int ret;
56 
57 	fwnode = dev_fwnode(&pdev->dev);
58 	if (!fwnode)
59 		return ERR_PTR(-ENODEV);
60 
61 	intr_ctrl = kmalloc(sizeof(*intr_ctrl), GFP_KERNEL);
62 	if (!intr_ctrl)
63 		return ERR_PTR(-ENOMEM);
64 
65 	intr_ctrl->pci_dev = pdev;
66 
67 	intr_ctrl->irq_domain = irq_domain_create_linear(fwnode, 1, &pci_dev_irq_domain_ops,
68 							 intr_ctrl);
69 	if (!intr_ctrl->irq_domain) {
70 		pci_err(pdev, "Failed to create irqdomain\n");
71 		return ERR_PTR(-ENOMEM);
72 	}
73 
74 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_INTX);
75 	if (ret < 0) {
76 		pci_err(pdev, "Unable alloc irq vector (%d)\n", ret);
77 		goto err_remove_domain;
78 	}
79 	intr_ctrl->irq = pci_irq_vector(pdev, 0);
80 	ret = request_irq(intr_ctrl->irq, pci_dev_irq_handler, IRQF_SHARED,
81 			  pci_name(pdev), intr_ctrl);
82 	if (ret) {
83 		pci_err(pdev, "Unable to request irq %d (%d)\n", intr_ctrl->irq, ret);
84 		goto err_free_irq_vector;
85 	}
86 
87 	return_ptr(intr_ctrl);
88 
89 err_free_irq_vector:
90 	pci_free_irq_vectors(pdev);
91 err_remove_domain:
92 	irq_domain_remove(intr_ctrl->irq_domain);
93 	return ERR_PTR(ret);
94 }
95 
96 static void pci_dev_remove_intr_ctrl(struct pci_dev_intr_ctrl *intr_ctrl)
97 {
98 	free_irq(intr_ctrl->irq, intr_ctrl);
99 	pci_free_irq_vectors(intr_ctrl->pci_dev);
100 	irq_dispose_mapping(irq_find_mapping(intr_ctrl->irq_domain, 0));
101 	irq_domain_remove(intr_ctrl->irq_domain);
102 	kfree(intr_ctrl);
103 }
104 
105 static void devm_pci_dev_remove_intr_ctrl(void *intr_ctrl)
106 {
107 	pci_dev_remove_intr_ctrl(intr_ctrl);
108 }
109 
110 static int devm_pci_dev_create_intr_ctrl(struct pci_dev *pdev)
111 {
112 	struct pci_dev_intr_ctrl *intr_ctrl;
113 
114 	intr_ctrl = pci_dev_create_intr_ctrl(pdev);
115 	if (IS_ERR(intr_ctrl))
116 		return PTR_ERR(intr_ctrl);
117 
118 	return devm_add_action_or_reset(&pdev->dev, devm_pci_dev_remove_intr_ctrl, intr_ctrl);
119 }
120 
121 struct lan966x_pci {
122 	struct device *dev;
123 	int ovcs_id;
124 };
125 
126 static int lan966x_pci_load_overlay(struct lan966x_pci *data)
127 {
128 	u32 dtbo_size = __dtbo_lan966x_pci_end - __dtbo_lan966x_pci_begin;
129 	void *dtbo_start = __dtbo_lan966x_pci_begin;
130 
131 	return of_overlay_fdt_apply(dtbo_start, dtbo_size, &data->ovcs_id, dev_of_node(data->dev));
132 }
133 
134 static void lan966x_pci_unload_overlay(struct lan966x_pci *data)
135 {
136 	of_overlay_remove(&data->ovcs_id);
137 }
138 
139 static int lan966x_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
140 {
141 	struct device *dev = &pdev->dev;
142 	struct lan966x_pci *data;
143 	int ret;
144 
145 	/*
146 	 * On ACPI system, fwnode can point to the ACPI node.
147 	 * This driver needs an of_node to be used as the device-tree overlay
148 	 * target. This of_node should be set by the PCI core if it succeeds in
149 	 * creating it (CONFIG_PCI_DYNAMIC_OF_NODES feature).
150 	 * Check here for the validity of this of_node.
151 	 */
152 	if (!dev_of_node(dev))
153 		return dev_err_probe(dev, -EINVAL, "Missing of_node for device\n");
154 
155 	/* Need to be done before devm_pci_dev_create_intr_ctrl.
156 	 * It allocates an IRQ and so pdev->irq is updated.
157 	 */
158 	ret = pcim_enable_device(pdev);
159 	if (ret)
160 		return ret;
161 
162 	ret = devm_pci_dev_create_intr_ctrl(pdev);
163 	if (ret)
164 		return ret;
165 
166 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
167 	if (!data)
168 		return -ENOMEM;
169 
170 	pci_set_drvdata(pdev, data);
171 	data->dev = dev;
172 
173 	ret = lan966x_pci_load_overlay(data);
174 	if (ret)
175 		return ret;
176 
177 	pci_set_master(pdev);
178 
179 	ret = of_platform_default_populate(dev_of_node(dev), NULL, dev);
180 	if (ret)
181 		goto err_unload_overlay;
182 
183 	return 0;
184 
185 err_unload_overlay:
186 	lan966x_pci_unload_overlay(data);
187 	return ret;
188 }
189 
190 static void lan966x_pci_remove(struct pci_dev *pdev)
191 {
192 	struct lan966x_pci *data = pci_get_drvdata(pdev);
193 
194 	of_platform_depopulate(data->dev);
195 
196 	lan966x_pci_unload_overlay(data);
197 }
198 
199 static struct pci_device_id lan966x_pci_ids[] = {
200 	{ PCI_DEVICE(PCI_VENDOR_ID_EFAR, 0x9660) },
201 	{ }
202 };
203 MODULE_DEVICE_TABLE(pci, lan966x_pci_ids);
204 
205 static struct pci_driver lan966x_pci_driver = {
206 	.name = "mchp_lan966x_pci",
207 	.id_table = lan966x_pci_ids,
208 	.probe = lan966x_pci_probe,
209 	.remove = lan966x_pci_remove,
210 };
211 module_pci_driver(lan966x_pci_driver);
212 
213 MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
214 MODULE_DESCRIPTION("Microchip LAN966x PCI driver");
215 MODULE_LICENSE("GPL");
216